Grandmaster Wesley So took the measure of Jeffrey Xiong of the United States, beating the 13-year-old American chess phenom in the fourth round of the Millionaire's chess tournament at the Planet Hollywood Resort & Casino.

Yu Yangyi of China is showing the way with four points and So is tied for second to sixth places, half a point behind, in the hectic four-day tournament that offers US$100,000 to the champion.

Exploiting Xiong's relative inexperience, the 21-year-old So steered the Indian Game into unfamiliar lines to win after 44 moves.

"Wesley has more experience, so we tried to capitalize on that," said Paul Truong, who coaches the Webster University NCAA champion team with wife Susan Polgar, a former women's world champion.

Sharing second to sixth places with So is Webster teammate Roby Robson, American Alexandr Lenderman, Daniel Naroditsky, also of the U.S. and Ecuadoran Carlos Matamoros, who is now based in the U.S.

With the white pieces, So faces Lenderman in the pivotal fifth round Saturday that is expected to untangle the logjam at the top of the US$1 million tournament, the richest ever in chess history.

The tournament calls for a seven-round Swiss system after which the top four players advance to the finals on Monday. The finalists play knock-out matches and the winner emerges champion in the Open section.

"The goal is to get there [the finals]," said Truong. 'We'll take it from there in terms of strategy."

Three other Filipino grandmasters have slim chances of qualifying for the finals, with Julio Sadorra on three points and Regelio Barcenilla and Ricardo de Guzman at two points each.

The youngest of 32 Open section tournament participants, Xiong drew raves by winning his first three games, including victories over two high-rated grandmasters.

"This boy and surely will earn his grandmaster's norm very soon," said Truong of Xiong, who is an international master.